Trying to get a usable tach signal. Yes, I've heard of autometer # 9117 little tach signal box. I would just rather spend a dollar on a resistor than 80-90 dollars on the tach adapter. It's an autometer monster tach w/ shift light. I'm trying to wire in a resistor for a little "bump up" voltage to raise the signal. My concern is that I have read that 3 different resistors have been used (4K, 2.2K, and something else). I just want to be right the first time and not fry my tach. Anyone know anything about this?